THE MONTHLY BULLETIN. 377 



small, pale colored creature without wings, and is called a nymph. 

 Feeding is immediately begun, the insect grows, molts or sheds its skin 

 five times, and after each molt the wings appear larger until they are 

 fully developed and the insect is mature, which requires a period of 

 about eighteen days. 



The season is now about the first of June (this varying with the 

 locality and year) when the first of these that have hatched from eggs 

 in the spring have wings and fly about more or less actively. This is 

 the time, as I shall point out later, when spraying can be done to best 

 advantage for the young or nymphs. At this time also the old hoppers 

 that have remained over winter begin to die off and are all gone by mid- 

 summer. This second or spring generation deposits eggs in July and 

 August and die off in September and October. The eggs that these 

 have deposited give rise to young which are maturing in August, Sep- 

 tember ard October, and these stay with the vine until the leaves fall, 

 v.'hen they take to the more varied diet during the winter and come on 

 to the vine again in the following spring. There are thus two genera- 

 tions in a season, the young of the first beginning to appear about the 

 first of May and the young of the second generation from about the first 

 of July, or sooner in the earlier sections. 



Control Measures. 



From the practical grower 's point of view the most important thing 

 concerning a pest is how to control it, or how to keep it under subjection 

 to the extent of not seriously damaging the crop. It should be under- 

 stood at the outset that the grape-leaf hopper is a very difficult insect to 

 handle successfully, and in my opinion the last word along this line still 

 remains to be said. The most important factor that militates against 

 successful control with this insect i.s its activity in the adult stage. The 

 full grown hoppers readily escape before any spray. Spraying is like- 

 wise of no avail against the eggs, for these are securely tucked away 

 beneath the surface tissue of the leaves. Spraying will, however, kill 

 the young. Another drawback to the control of this insect, or any 

 grape insect for that matter, is that the expense is likely to extend too 

 far into the margin of profit from the crop. 



General Cultural Practices. 



Some growers believe in plowing the vineyard in the winter or early 

 spring with a view to reducing the hoppers. Plowing will not kill the 

 hoppers directly, for they are active enough to escape readily before the 

 plow. During cold or wet weather, when the hoppers are more dormant, 

 a few may be turned under, but, generally, plowing is not done under 

 such weather conditions. Plowing may indirectly affect them, however, 

 by depriving them of food in turning under the green growth in the 

 vineyard or of destroying their hibernating places as represented by the 

 accumulation of leaves or other rubbish. Turning sheep in the vineyard 

 in the fall to eat the leaves, as is sometimes practiced, has the same 

 result. 



